scholarly journals Combined anaerobic-aerobic and UV/H2O2 processes for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Ciro F. Lecompte
Keyword(s):  
Flow Rate ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Secondary Effluent ◽  
Slaughterhouse Wastewater ◽  
Loading Rates ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Toc Removal ◽  
Single Process

The biological treatment of a synthetic slaughterhouse wastewater (SSWW) was studied using an anaerobic baffled reactor (ABR) and an aerobic activated sludge (AS) at a laboratory scale, with total organic carbon (TOC) loading rates of 0.03–1.01 g/(L.day), total nitrogen (TN) loading rates of 0.01–0.19 g/(L.day), and a flow rate of 2.93 to 11.70 mL/min in continuous mode. Results revealed that combined anaerobic-aerobic processes had higher efficiency to treat SSWW than a single process. Up to 96.36% TOC, 80.53% TN, and 99.38% 5-day carbonaceous biochemical oxygen demand (CBOD5) removal from an influent concentration of 1,008.85 mgTOC/L, 419.77 mgTN/L, and 640 mgCBOD5/L at the hydraulic retention time (HRT) of 6.24 days and a flow rate of 3.75 mL/min was achieved. The UV/H2O2 process was studied to treat a secondary effluent of SSWW with TOC loadings of 64.88–349.84 mg/L. Up to 75.22% TOC and 84.38% CBOD5 removal were obtained for an influent concentration of 64.88 mgTOC/L at the HRT of 3 h with H2O2 concentration of 900 mg/L. An optimum molar ratio dosage of 13.87 mgH2O2/mgTOCin was also obtained. Combined anaerobic-aerobic and UV/H2O2 processes enhanced the biodegradability of the TOC, TN, and CBOD5 present in the SSWW. Up to 99.98% TOC, 82.84% TN, and 99.69% CBOD5 overall removals were obtained for an influent concentration of 1,004.88 mgTOC/L, 200.03 mgTN/L, and 640 mgCBOD5/L at the HRT of 4 days and a flow rate of 5.90 mL/min. A cost-effectiveness analysis (CEA) was performed for the optimum conditions for the SSWW treatment by optimizing total electricity cost and HRT, in which the combined anaerobic-aerobic and UV/H2O2 processes had an optimal TOC removal of 92.46% at an HRT of 41 h, a cost of $1.25/kg of TOC removed, and $11.60/m3 of treated SSWW. This process reaches a maximum TOC removal of 99% in 76.5 h with an estimated cost of $2.19/kg TOC removed and $21.65/m3 treated SSWW.

scholarly journals Combined anaerobic-aerobic and UV/H2O2 processes for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Ciro F. Lecompte
Keyword(s):  
Flow Rate ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Secondary Effluent ◽  
Slaughterhouse Wastewater ◽  
Loading Rates ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Toc Removal ◽  
Single Process

The biological treatment of a synthetic slaughterhouse wastewater (SSWW) was studied using an anaerobic baffled reactor (ABR) and an aerobic activated sludge (AS) at a laboratory scale, with total organic carbon (TOC) loading rates of 0.03–1.01 g/(L.day), total nitrogen (TN) loading rates of 0.01–0.19 g/(L.day), and a flow rate of 2.93 to 11.70 mL/min in continuous mode. Results revealed that combined anaerobic-aerobic processes had higher efficiency to treat SSWW than a single process. Up to 96.36% TOC, 80.53% TN, and 99.38% 5-day carbonaceous biochemical oxygen demand (CBOD5) removal from an influent concentration of 1,008.85 mgTOC/L, 419.77 mgTN/L, and 640 mgCBOD5/L at the hydraulic retention time (HRT) of 6.24 days and a flow rate of 3.75 mL/min was achieved. The UV/H2O2 process was studied to treat a secondary effluent of SSWW with TOC loadings of 64.88–349.84 mg/L. Up to 75.22% TOC and 84.38% CBOD5 removal were obtained for an influent concentration of 64.88 mgTOC/L at the HRT of 3 h with H2O2 concentration of 900 mg/L. An optimum molar ratio dosage of 13.87 mgH2O2/mgTOCin was also obtained. Combined anaerobic-aerobic and UV/H2O2 processes enhanced the biodegradability of the TOC, TN, and CBOD5 present in the SSWW. Up to 99.98% TOC, 82.84% TN, and 99.69% CBOD5 overall removals were obtained for an influent concentration of 1,004.88 mgTOC/L, 200.03 mgTN/L, and 640 mgCBOD5/L at the HRT of 4 days and a flow rate of 5.90 mL/min. A cost-effectiveness analysis (CEA) was performed for the optimum conditions for the SSWW treatment by optimizing total electricity cost and HRT, in which the combined anaerobic-aerobic and UV/H2O2 processes had an optimal TOC removal of 92.46% at an HRT of 41 h, a cost of $1.25/kg of TOC removed, and $11.60/m3 of treated SSWW. This process reaches a maximum TOC removal of 99% in 76.5 h with an estimated cost of $2.19/kg TOC removed and $21.65/m3 treated SSWW.

scholarly journals Combined anaerobic baffled reactor and UV/H2O2 process for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Weihua Cao
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Model ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Combined Processes ◽  
Slaughterhouse Wastewater ◽  
Anaerobic Baffled Reactor ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Removal Efficiencies

A laboratory scale for the combined processes of a biological anaerobic baffled reactor (ABR) and a UV/hydrogen peroxide (H2O2) was used to investigate the treatment of a synthetic slaughterhouse wastewater with various influent concentrations and various hydraulic retention times (HRT) at room temperature in this study. The results showed that the removal efficiencies of total organic carbon (TOC), chemical oxygen demand (COD), and 5-day carbonaceous biochemical oxygen demand (CBOD5) of the wastewater with an influent concentration of 973 mgTOC/L and a HRT of 3.8 days reached 89.9, 97.7, and 96.6%, respectively, in the ABR process, whilst the removal efficiency of TOC in the UV/H₂O₂ process reached 50.8% at a HRT of 3.6 h and H2O2 dosage of 1371 mgH2O2/L, leading to 95.0% of overall TOC removal of the combined processes. For comparison, the removal efficiencies of TOC, COD, and CBOD5 of the synthetic wastewater with an influent concentration of 158 mgTOC/L reached 64.9, 81.9, and 84.3% respectively, at an HRT of 2.5 h and a H2O2 dosage of 1371 mgH2O2/L in UV/H2O2 process alone. An optimum value of hydrogen peroxide was found to be 3.5 (mgH2O2/L)/(mgTOCin/L.h). After the ABR treatment, the ration of CBOD5/COD of the untreated wastewater changed from 0.4 to 0.6 and 0.5 to 0.2, and the ratio of COD/TOC of the wastewater decreased from 2.4 to 0.5 and 2.2 to 2.0, at the HRT of 3.8 and 0.9 days, respectively, indicating that the biodegradability of the wastewater was enhanced at a longer HRT in the ABR process. Afer the UV/H2O2 process treatment, the ratios of CBOC5/COD of the untreated and the ABR treated wastewater increased from 0.4 to 0.6 and 0.3 to 0.5, and the ratios of COD/TOC of the wastewaters decreased from 2.3 to 0.6 and 1.8 to 0.9, respectively, at the HRT of 2.5 h, indicating that the UV/H2O2 process had the ability to enhance the biodegradability of the wastewater. A kinetic model for the ABR process was obtained and used to evaluate the experimental findings. The parameters of the kinetic model for the ABR process were determined to be 3.1X10⁻2 for refractory coefficient, 0.4 for kinetic coefficient, 2.0 mg/L for half-saturation constant for hydrolyzed substrate, and 1.9 day⁻1 for the maximum specific growth rate of organism, respectively. The optimum HRT and the minimum total electricity cost were determined to be 78.9 h and $11.45 /kg of TOC removed for the ABR process, with 1000 mgTOC/L of the wastewater influent concentration, leading to 100.0 mgTOC/L of the effluent concentration which met the disposal level in Canada.

scholarly journals Combined anaerobic baffled reactor and UV/H2O2 process for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Weihua Cao
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Model ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Combined Processes ◽  
Slaughterhouse Wastewater ◽  
Anaerobic Baffled Reactor ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Removal Efficiencies

A laboratory scale for the combined processes of a biological anaerobic baffled reactor (ABR) and a UV/hydrogen peroxide (H2O2) was used to investigate the treatment of a synthetic slaughterhouse wastewater with various influent concentrations and various hydraulic retention times (HRT) at room temperature in this study. The results showed that the removal efficiencies of total organic carbon (TOC), chemical oxygen demand (COD), and 5-day carbonaceous biochemical oxygen demand (CBOD5) of the wastewater with an influent concentration of 973 mgTOC/L and a HRT of 3.8 days reached 89.9, 97.7, and 96.6%, respectively, in the ABR process, whilst the removal efficiency of TOC in the UV/H₂O₂ process reached 50.8% at a HRT of 3.6 h and H2O2 dosage of 1371 mgH2O2/L, leading to 95.0% of overall TOC removal of the combined processes. For comparison, the removal efficiencies of TOC, COD, and CBOD5 of the synthetic wastewater with an influent concentration of 158 mgTOC/L reached 64.9, 81.9, and 84.3% respectively, at an HRT of 2.5 h and a H2O2 dosage of 1371 mgH2O2/L in UV/H2O2 process alone. An optimum value of hydrogen peroxide was found to be 3.5 (mgH2O2/L)/(mgTOCin/L.h). After the ABR treatment, the ration of CBOD5/COD of the untreated wastewater changed from 0.4 to 0.6 and 0.5 to 0.2, and the ratio of COD/TOC of the wastewater decreased from 2.4 to 0.5 and 2.2 to 2.0, at the HRT of 3.8 and 0.9 days, respectively, indicating that the biodegradability of the wastewater was enhanced at a longer HRT in the ABR process. Afer the UV/H2O2 process treatment, the ratios of CBOC5/COD of the untreated and the ABR treated wastewater increased from 0.4 to 0.6 and 0.3 to 0.5, and the ratios of COD/TOC of the wastewaters decreased from 2.3 to 0.6 and 1.8 to 0.9, respectively, at the HRT of 2.5 h, indicating that the UV/H2O2 process had the ability to enhance the biodegradability of the wastewater. A kinetic model for the ABR process was obtained and used to evaluate the experimental findings. The parameters of the kinetic model for the ABR process were determined to be 3.1X10⁻2 for refractory coefficient, 0.4 for kinetic coefficient, 2.0 mg/L for half-saturation constant for hydrolyzed substrate, and 1.9 day⁻1 for the maximum specific growth rate of organism, respectively. The optimum HRT and the minimum total electricity cost were determined to be 78.9 h and $11.45 /kg of TOC removed for the ABR process, with 1000 mgTOC/L of the wastewater influent concentration, leading to 100.0 mgTOC/L of the effluent concentration which met the disposal level in Canada.

Anaerobic digestion of primary sludge from chemical pre-precipitation

1997 ◽  
Vol 36 (6-7) ◽  
pp. 357-365 ◽  
Author(s):  
Wouter Ghyoot ◽  
Willy Verstraete
Keyword(s):  
Anaerobic Digestion ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Municipal Sewage ◽  
Primary Sludge ◽  
Loading Rates ◽  
Volatile Solids ◽  
Feasible Option ◽  
Kjeldahl Nitrogen

Many existing wastewater treatment plants are to be upgraded for phosphorus removal. In our study, ferric chloride was used as a coagulant in pre-precipitation of municipal sewage. Using a Fe/P molar ratio of 0.8, removal efficiencies for suspended solids (64%), chemical oxygen demand (50%), Kjeldahl nitrogen (22%), total phosphorus (43%) and orthophosphate (51%) were obtained. Anaerobic digestion of raw primary sludge yielded a volatile solids (VS) destruction of 35% at VS loading rates of 0.60 to 0.79 kg VS/m3.d. Digestion of chemically enriched primary sludge (CEP-sludge) yielded a VS destruction of 57% at a VS loading rate of 1.36 kgVS/m3.d. Comparison of the methane production per kg VS destroyed (519 to 612 1 CH4/kgVS destroyed for primary sludge, 299 to 395 1 CH4/kgVS destroyed for CEP-sludge) evidenced a change in the composition of the organic material after precipitation with coagulants; the latter sludge was enriched in less reduced compounds. The precipitated phosphorus was not released to the supernatant during anaerobic digestion. No evidence for reduced digester stability was found for digestion of CEP-sludge. These results indicate that retro-fitting a plant by chemical pre-precipitation and subsequent anaerobic digestion of the CEP-sludge is a feasible option.

A comparative treatment of bleaching wastewater by physicochemical processes

2017 ◽  
Vol 76 (9) ◽  
pp. 2367-2379 ◽  
Author(s):  
Ninad Oke ◽  
Swati Singh ◽  
Anurag Garg
Keyword(s):  
Mixing Time ◽  
Oxygen Demand ◽  
Chloride Ion ◽  
Paper Mill ◽  
Ion Concentration ◽  
Treated Wastewater ◽  
Molar Ratio ◽  
Chlorinated Organic Compounds ◽  
H2o2 Treatment ◽  
Toc Removal

Abstract The bleaching effluent discharged from a pulp and paper mill contains chlorinated organic compounds which are toxic to living matter. Physicochemical treatments such as coagulation and different advanced oxidation processes (AOPs) were employed for combined bleaching effluent generated from the first two stages (i.e. chlorination and alkali extraction) (pH = 3.5, chemical oxygen demand (COD) = 1,920 mg/L, and total organic carbon (TOC) = 663 mg/L). At optimum conditions (pH = 7.5, polyaluminium chloride (PAC) dose = 3.84 g/L and slow mixing time = 25 min), ∼68% removal in UV254 and ∼23% TOC removal was obtained during coagulation. Among various AOPs, UV/Fe2+/TiO2/H2O2 system showed the highest TOC and COD removals (∼78%) after 2 h duration (Fe2+:H2O2 molar ratio = 1:100). After the AOP process, chloride ion concentration and biodegradability of the treated wastewater was increased to 2,762 mg/L and 0.46 from an initial value of 2,131 mg/L and 0.29, respectively. The wastewater and sludge analysis showed oxidation and adsorption as the major mechanisms for organics removal. Upon reuse of the regenerated catalysts, TOC removal was reduced significantly. It was found that three times more sludge per unit TOC removal was generated after coagulation in comparison to that produced after UV/Fe2+/TiO2/H2O2 treatment.

scholarly journals Degradation of high-concentration p-nitrophenol by Fenton oxidation

2020 ◽  
Vol 81 (10) ◽  
pp. 2260-2269
Author(s):  
Xiao Qing Lin ◽  
Wei Min Kong ◽  
Xiao Lin
Keyword(s):  
Degradation Rate ◽  
Removal Rate ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Fenton Oxidation ◽  
Utilization Efficiency ◽  
Molar Ratio ◽  
High Concentration ◽  
Initial Concentration ◽  
Toc Removal

Abstract This work aimed to degrade high-concentration p-nitrophenol (PNP) by Fenton oxidation. We studied various reaction parameters during Fenton oxidation, such as the iron dosage (as Fe2+), the initial concentration and temperature of PNP, and the dosage of hydrogen peroxide (H2O2), especially the influence of temperature on the PNP degradation rate and degree. Under the addition of the same molar ratio of H2O2/Fe2+ and H2O2 dosage according to the theoretical stoichiometry, the PNP degradation rate and the removal rate of total organic carbon (TOC) increased significantly with the increase in the initial PNP concentration. Moreover, the oxidative degradation effect was significantly affected by temperature. The increased reaction temperature not only significantly reduced the Fe2+ dosage, but also greatly promoted the removal rate of chemical oxygen demand (COD) and TOC, and improved the utilization efficiency of H2O2. For example, when the initial concentration of PNP was 4,000 mg·L−1, and the dosage of Fe2+ was 109 mg·L−1 (H2O2/Fe2+ = 200), the removal rates of COD and TOC at 85 °C reached 95% and 71% respectively. Both were higher than the 93% COD removal rate and 44% TOC removal rate when the dosage of Fe2+ was 1,092 mg·L−1 (H2O2/Fe2+ = 20) at room temperature.

Field study on N2O emission from subsurface wastewater infiltration system under variable loading rates and drying-wetting cycles

2017 ◽  
Vol 76 (8) ◽  
pp. 2158-2166 ◽  
Author(s):  
Ying-Hua Li ◽  
Hai-Bo Li ◽  
Xin-Yang Xu ◽  
Si-Yao Xiao ◽  
Si-Qi Wang ◽  
...  
Keyword(s):  
Field Study ◽  
Conversion Rate ◽  
Oxygen Demand ◽  
N2o Emission ◽  
Conversion Ratio ◽  
Gas Chromatograph ◽  
Variable Loading ◽  
N2o Production ◽  
Loading Rates ◽  
Operation Conditions

In this field study, the impacts of influent loadings and drying-wetting cycles on N2O emission in a subsurface wastewater infiltration (SWI) system were investigated. N2O emitted under different operation conditions were quantified using static chamber and gas chromatograph techniques. N2O conversion rate decreased from 6.6 ± 0.1% to 2.7 ± 0.1% with an increase in hydraulic loading (HL) from 0.08 to 0.24 m3/m2·d. By contrast, N2O conversion rate increased with increasing pollutant loading (PL) up to 8.2 ± 0.5% (PL 4.2 g N/m2·d) above which conversion rate decreased, confirming that N2O production was under the interaction of nitrification and denitrification. Taking into consideration the pollutants (chemical oxygen demand (COD), NH4+-N, NO3−-N and total nitrogen (TN)) removal ratio and N2O emission, optimal loading ranges and drying-wetting modes were suggested as HL 0.08–0.12 m3/m2·d, PL 3.2–3.7 g N/m2·d and 12 h:12 h, respectively. The results revealed that in SWI systems, conversion ratio of influent nitrogen to N2O could be between 4.5% and a maximum of 7.0%.

scholarly journals Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hsiao-Ching Chen ◽  
Hen-Yi Ju ◽  
Tsung-Ta Wu ◽  
Yung-Chuan Liu ◽  
Chih-Chen Lee ◽  
...  
Keyword(s):  
Flow Rate ◽  
Immobilized Lipase ◽  
Continuous Production ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Molar Ratio ◽  
System Response ◽  
Biodiesel Synthesis ◽  
Substrate Molar Ratio ◽  
Molar Conversion

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in atert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature52.1∘C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were83.31±2.07% and82.81±.98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

Optimization and statistical analysis of sono-Fenton treated wastewater of food industry using reactor by response surface method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vijay A. Juwar ◽  
Ajit P. Rathod
Keyword(s):  
Reaction Time ◽  
Response Surface ◽  
Food Industry ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Experimental Result ◽  
Molar Ratio

Abstract The present study deals with the treatment of complex waste (WW) treated for removal of chemical oxygen demand (COD) of the food industry by a sono-Fenton process using a batch reactor. The response surface methodology (RSM) was employed to investigate the five independent variables, such as reaction time, the molar ratio of H2O2/Fe2+, volume ratio of H2O2/WW, pH of waste, and ultrasonic density on COD removal. The experimental data was optimized. The optimization yields the conditions: Reaction time of 24 min, HP:Fe molar ratio of 2.8, HP:WW volume ratio of 1.9 ml/L, pH of 3.6 and an ultrasonic density of 1.8 W/L. The predicted value of COD was 91% and the experimental result was 90%. The composite desirability value (D) of the predicted percent of COD removal at the optimized level of variables was close to one (D = 0.991).

Tilapia rearing with high rate algal pond effluent: ammonia surface loading rates and stocking densities effects

2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana
Keyword(s):  
Weight Gain ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
High Rate ◽  
Surface Loading ◽  
Loading Rates ◽  
Total Weight Gain ◽  
Low Weight ◽  
Total Ammonia

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.

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